Insect genetic technologies are enabling researchers to conceive of new ways to control insects and to improve on established control methods.
In mosquitoes there have been a number of ideas for using genetic technologies to reduce mosquito populations or to alter the vectoral capacity of wild mosquitoes so that pathogen transmission and the incidence of disease are reduced. Recently there has been a description of an Anopheles gambiae eradication strategy based on the release of males that contain a genetic system that results in only Y-containing sperm and all of their sons contain the same system leading eventually to a collapse of a population because of the absence of females (more>>). In a more general way, there has been some discussion recently from the “synthetic biology” community about how current gene editing technologies could be used to create ‘gene drive’ systems like those described in Anopheles gambiae, and that these genetic technologies warrant careful use, planning and consideration before they are ‘released’ (more>>).
A project originally funded by the Gates Foundation and targeting Dengue transmission by Aedes aegypti in Mexico took a somewhat different approach that did not require gene drives and resembled in many ways the traditional Sterile Insect Technique (SIT). The methods developed using transgenic technologies were distinctly different from SIT but the general idea of imposing on natural populations a large genetic load which, if sustained could reduce or locally eradicate populations, was very similar
This large project involved not only the creation of mosquitoes with relevant genotypes and phenotypes but also attempted to establish a framework by which future projects might be undertaken by dealing also with the social and political ramifications of such a biological control project.
Much was learned and Ramsey et al (2014) provide a useful report of their experiences. This is worth reading and it leaves one with an appreciation of the multifaceted nature of implementing a control strategy that is based on technology that can elicit visceral negative reactions and which presents, arguably, a somewhat novel set of risks. The groundwork for such a project must be laid out carefully for it to be successful. It is also essential that it be done “correctly” and successfully if insect biologists hope to use these technologies in the future.
Note that some of the authors were also involved in drafting the recent guidance document from the World Health Organization on the release of transgenic or genetically modified mosquitoes (more>>).
Ramsey JM, Bond JG, Macotela ME, Facchinelli L, Valerio L, et al. (2014) A Regulatory Structure for Working with Genetically Modified Mosquitoes: Lessons from Mexico. PLoS Negl Trop Dis 8(3): e2623.doi:10.1371/journal.pntd.0002623